Photographic color developing process

ABSTRACT

1. THE PROCESS FOR THE PRODUCTION OF COLORED PHOTOGRAPHIC IMAGES INCLUDING THE STEPS OF IMAGEWISE EXPOSING A COLOR PHOTOGRAPHIC MATERIAL CONTAINING AT LEAST ONE SILVER HALIDE LAYER, DEVELOPING THE EPOSED MATERIAL WITH COLOR-DEVELOPER TO FORM THE DYE-IMAGE IN THE PRESENCE OF COLOR-COUPLLERS AND TREATING THE MATERIAL WITH A BATH THAT BLEACHES AND FIXES THE DEVELOPED MATERIAL TO REMOVE DEVELOPED SILVER AND RESIDUAL SILVER HALIDE, WHEREIN THE IMPROVEMENT COMPRISES THE BLEACHING OF THE DEVELOPED MATERIAL IS IN THE PRESENCE OF A WATER-SOLUBLE OXIME IN THE BATH, CORRESPONDING TO THE FOLLOWING FORMULA:   (-R1-R2-)&gt;C=N-OH   IN WHICH R1=HYDROGEN OR AN ALIPHATIC GROUP WITH UP TO 12 CARBON ATOMS AND R2=AN ALIPHATIC GROUP WITH UP TO 12 CARBON ATOMS OR R1 AND R2 TOGETHER REPRESENT THE RING MEMBERS REQUIRED TO COMPLETE A SATURATED CARBOCYCLIC OR HETEROCYCLIC 5- OR 6-MEMBERED RING, THE AMOUNT OF OXIME BEING SUCH THAT IT REDUCES THE FORMATION OF COLOR FOG DURING BLEACHING.

United States Patent Oflice 3,843,367 Patented Oct. 22, 1974 U.S. Cl. 96-56 4 Claims ABSTRACT OF THE DISCLOSURE For the prevention of bleach-induced fogging color photographic material is treated after color development in a bleaching or bleach-fixing bath containing a watersoluble aliphatic carbocyclic or heterocyclic oxime. This treatment is particularly suitable in high-speed processing at elevated temperature. Rinsing after color development can be omitted.

This invention relates to a photographic color developing process, which is intended in particular for high-speed processing, in which oximes are used as anti-bleach-fogging agents.

It is known that colored photographic images can be produced by chromogenic development, i.e. by developing silver halide emulsion layers, which have been exposed image-wise in the presence of suitable color couplers by means of suitable color-forming developer substances, known as color developers, the oxidation product of the developer substances being formed in correspondence with the silver image and reacting with the color coupler to form a dye image. Aromatic compounds containing primary amino groups, especially those of the p-phenylene diamine type, are generally used as color developers. After color development, the photographic material has to be treated with a bleaching bath and a fixing bath, or with a combined bleach and fixing bath in order to remove image silver and any silver halide still present after development. The bleaching substances used are oxidizing agents which oxidize residues of color developers which are still present in the photographic emulsion from the developing process and which, in the presence of color couplers, lead to the undesirable formation of a fog of an azomethine or indoquinone dye, referred to hereinafter as bleach-induced fogging.

In order to avoid this fault in processing, conventiona processing methods prescribe either rinsing the material after development for periods that are disproportionately long in relation to the overall processing time, or pretreating the material with a stopping or stop-fixing bath before the bleaching or bleach-fixing operation. Both measures are obstacles to really high-speed processing and involve additional cost. In another method, the bleaching or bleach-fixing operation is carried out in the presence of special substances which prevent bleach-induced fogging. Examples of substances which have been recommended for this purpose include N-hydroxymorpholines, N-aminomorpholines, certain 3-pyrazolidone derivatives and certain amino phenol derivatives. However they are either relatively unstable in the bleaching or bleach-fixing bath or, where they do show adequate stability, are not sufiiciently effective.

The object of the invention is to improve bleaching or bleach-fixing baths for color photographic processes, especially for high-speed processing, by the addition of substances which prevent the formation of bleach-induced fogs and which are sutficiently stable in the baths.

A photographic color-developing process for the production of colored images using a. color photographic material with at least one image-wise exposed silver halide emulsion layer by color development, bleaching and fixing or bleach-fixing, has now been found in which the bleaching or bleach-fixing operation is carried out in the presence of a water-soluble, aliphatic, carbocyclic or heterocyclic oxime.

Oximes corresponding to the following formula are particularly suitable:

In this formula,

R =hydrogen or an aliphatic, preferably saturated, radical with up to 12, preferably up to 5 carbon atoms which may be substituted, for example with halogen, such as chlorine, hydroxy, short-chain alkoxy radicals with preferably up to 3 carbon atoms such as methoxy, carboxy, esterified carboxy, preferably carboxy esterified with short-chain aliphatic alcohols, or an oxime p;

R =an aliphatic, preferably saturated, radical with up to 12, preferably up to 5 carbon atoms, which may be substituted, for example with halogen such as chlorine, hydroxy, short-chain alkoxy radicals with preferably up to 3 carbon atoms such as methoxy, carboxy, esterified carboxy, preferably carboxy esterified with shortchain aliphatic alcohols, or an. oxime group,

or R and R together may represent the ring members required to complete a preferably saturated, carbocyclic or heterocyclic 5- or 6-membered ring such as, for example, cyclopentane, cyclohexane, hexahydropyridine, hexahydropyrrole or the like.

Compounds in which R and/or R represent an aliphatic radical with up to 5 carbon atoms, are preferred.

The following are examples of suitable oximes:

HsC-

10. NOH

I The aforementioned substances are added to the bleaching or bleach-fixing bath preferably in quantities of from 0.5 to 10 g. per litre. It is also possible to pre-treat the material development briefly with an aqueous solution of the compounds according to the invention before the bleaching or bleach-fixing operation. In this case, it is advisable to use the oximes according to the invention in relatively high concentration. Useful results are obtained for example with aqueous pretreatment baths containing from 5 to 50 g. per litre of the oximes to be used in accordance with the invention.

The oximes can of course also be used in conventional methods of processing color-photographic materials, in which case intermediate rinsing is generally carried out between the developer bath, and the bleaching and fixing baths or the bleach-fixing bath. However, they are used with particular advantage in so-called high-speed processing which is preferably carried out at a slightly elevated temperature and in which the need for intermediate rinsing should be eliminated where possible. Although, as a rule, heavy bleach-induced fogging readily occurs in this case, it is effectively suppressed in the presence of the oximes.

The oximes are used with particular advantage in processing machines with small bath volumes, for example, table-top machines, so-called one-off developing machines and the like, being less suitable for large processing machines with correspondingly large bath volumes on account of the gradual decomposition governed by the pH- value of the processing bath.

The bleaching baths normally used in photography can be used as the bleaching or bleach-fixing bath. The bleaching substances are generally oxidizing agents which are able to oxidize metallic silver present in the photographic material into the silver salt. Preferred bleaches are iron (III) compounds, such as, for example, iron (III) chloride, potassium ferricyanide or the iron (III) salt of ethylenediaminetetraacetic acid.

Photographic bleach-fixing baths are photographic treatment baths in which bleaching oxidizing agents are combined with a silver salt solvent such as sodium thiosulfate or ammonium thiosulfate. Other complex-forming agents may also be present. Treatment with a bleach-fixing bath not only oxidizes the metallic silver into the silver salt but also subsequently dissolves out of the layer the silver salt formed. Bleaching and bleach-fixing baths are known in the photographic art. Reference is made for example to H. Berger Agfacolor, 6th Edition, pages 260 and 262, and to E. Mutter, Die wissenschaftliche und angewandte Photographie," Vol. IV (1967), pages 348, 352, 353 and 362.

Particularly favorable results are obtained by using the oximes in bleach-fixing baths with an increased sodium or ammonium thiosulfate content. Accordingly, the bleach-fixing baths according to the invention preferably contain 100 to 200 g. of sodium or ammonium thiosulfate per litre.

A further improvement is obtained where the oximes are used together with white couplers in the bleach-fixing baths. White couplers are substances which are able to react with color developer oxidation products without forming a dye. White couplers as such are known, for example, reference is made to German Pat. No. 1,155,675 wherein the preparation of white or colorless couplers can be effected by the process described as follows. It has now been found that the compounds with activated methylene groups couple with the oxidation products of the developer, not to form colored reaction products, but instead to form colorless reaction products, if one hydrogen atom in the activated methylene group of these compounds is replaced by a substituted or unsubstituted aliphatic, cyclo-aliphatic, aromatic or mixed aromaticaliphatic radical. Reference is also made to the article by W. Piischel in Mitteilungen aus den Forschungslaboratorien der Agfa-Gevaert AG, Vol. IV, page 352 (1964).

The. most favorable results are obtained with bleachfixing baths which, in addition to the oximes and a thiosulfate content which may be increased, contain from 1 to 5 g.. of a white coupler substance per litre.

The invention is illustrated by the following Example:

EXAMPLE An exposed color photographic multi-layer material was developed for seconds at 40 C. in a developer of the following composition:

6 g. of N-butyl-N-w-sulfobutyl-p-phenylenediamine 4 g. of anhydrous sodium sulfite 2 g. of hydroxylamine hydrochloride 100 g. of potassium carbonate 1 g. of potassium bromide made up with water to 1,000

The material was then stripped and treated for seconds at 40 C. with the following bleach-fixing bath:

3 g. of butanone-Z-oxinie 6 g. of the disodium salt of ethylenediaminetetracetic acid 40 g. of the iron (III) salt of ethylenediaminetetracetic acid 200 g. of ammonium thiosulfate 3 g. of l-(m-sulfophenyl)-3-methyl-4-isopropyl-5-pyrazolone 4 g. of anhydrous sodium sulfite made up with water to aforementioned bleach-fixing bath, showed excessively high fogging.

Equally favorable results are obtained with other aliphatic, cycloaliphatic or heterocyclic oximes of the kind described above.

We claim:

1. The process for the production of colored photographic images including the steps of imagewise exposing a color photographic material containing at least one silver halide layer, developing the exposed material with color-developer to form the dye-image in the presence of color-couplers and treating the material with a bath that bleaches and fixes the developed material to remove developed silver and residual silver halide, wherein the improvement comprises the bleaching of the developed material is in the presence of a water-soluble oxi-me in the bath, corresponding to the following formula:

in which R =hydrogen or an aliphatic group with up to 12 carbon atoms and R =an aliphatic group with up to 12 carbon atoms or R and R together represent the ring members required to complete a saturated carbocyclic or heterocyclic 5- or 6-membered ring,

the amount of oxime being such that it reduces the formation of color fog during bleaching.

2. A process as claimed in Claim 1, wherein the color developed material is bleach-fixed in a bleach-fixing bath containing the oxime in quantities of from 0.5 to 10 g. per litre.

3. A process as claimed in Claim 2, wherein the bleachfixing bath contains 100 to 200 g. of sodium or ammonium thiosulfate per litre.

4. A process as claimed in Claim 2; wherein the bleachfixing bath contains 1 to 5 g. of a white coupler per litre.

References Cited UNITED STATES PATENTS 2,675,314 4/1954 Vittum et al. Q 96-56 2,748,000 5/1956 Mader 9660 R 3,457,077 7/ 1969 Puschel et al 96--60 R RONALD H. SMITH, Primary Examiner R. L. SCHILLING, Assistant Examiner U.S. Cl. X.R. 96-60 R, BF 

1. THE PROCESS FOR THE PRODUCTION OF COLORED PHOTOGRAPHIC IMAGES INCLUDING THE STEPS OF IMAGEWISE EXPOSING A COLOR PHOTOGRAPHIC MATERIAL CONTAINING AT LEAST ONE SILVER HALIDE LAYER, DEVELOPING THE EPOSED MATERIAL WITH COLOR-DEVELOPER TO FORM THE DYE-IMAGE IN THE PRESENCE OF COLOR-COUPLLERS AND TREATING THE MATERIAL WITH A BATH THAT BLEACHES AND FIXES THE DEVELOPED MATERIAL TO REMOVE DEVELOPED SILVER AND RESIDUAL SILVER HALIDE, WHEREIN THE IMPROVEMENT COMPRISES THE BLEACHING OF THE DEVELOPED MATERIAL IS IN THE PRESENCE OF A WATER-SOLUBLE OXIME IN THE BATH, CORRESPONDING TO THE FOLLOWING FORMULA: 